No. Currently, a number of balancing mechanics take place to prevent one faction from controlling Wintergrasp forever -- giving one faction more shops to start, vehicles after one kill, etc. In the past, as soon as someone defended once, they would start to face increased opposition from an opposing faction immediately in the form of various buffs. Now, it will take two defenses before the scale is tipped against the defending faction (in an attempt to make it easier for the assaulting faction to win).

What this means, in short, is that the defending faction will be in a slightly better position after the first defense than they were previously.

The whole system seems relatively complex from what I've understood about it so far, so it's probably not quite this simple, but practically speaking, if you're a casual Wintergrasp player, you're probably not going to see any difference. However, if you make sure to be in WG every time that clock hits 0, you might notice some differences in the balancing mechanics.

on my server the alliance usually had full tenacity and controlled all but the fortress workshop but we would still hold them off nearly every single time. i don't expect them to hold on to WG any more than they did before the patch. FTH! :D